The group, assisted by producer Kim Fowley, consisted initially of singer/guitarist Joan Jett, bassist Michael Steele and drummer Sandy West. Steele left the band after only a few months in 1975 (and later joined The Bangles) She was replaced by a succession of bass players over the run of the group, including Peggy Foster, Jackie Fox, Vicki Blue, and Laurie McAllister. Lita Ford signed on within the first year of the band as lead guitarist after initially auditioning for bass. Cherie Currie joined as lead vocalist. Jackie Fox left the group in 1977, during the Japanese tour. Shortly after the band returned to the US, Cherie Currie left the Runaways and Joan Jett took over as lead vocalist.
Disagreement between band members included the musical style; Joan Jett wanted the band to take a musical change, shifting towards punk rock/glam rock while Lita Ford, backed by drummer Sandy West, wanted to continue playing hard rock/heavy metal music. Neither would accept the other's point of view. The Runaways played their last ever concert on New Year's Eve, 1978 at the Cow Palace near San Francisco and officially broke up in April 1979.
In 1985, Kim Fowley still owned the rights to the Runaways name and brought an entirely new group of girls together to record an album. This incarnation consisted of Gayle Welch, Missy Bonilla, Denise Pryor and Kathrine Dombrowski. They only released one album together, Young And Fast in 1987, and disbanded soon after its release.